Last spring frost
Apr 26
Frost Dates for Jacobus, PA
First fall frost
Oct 19
Growing season
177 days
Hardiness zone
7a
In an average year around Jacobus, PA, the last spring frost (32°F) is about Apr 26 and the first fall frost is about Oct 19, giving roughly a 177-day growing season. To be safe most years, wait until Apr 7 before setting out tender plants.
Last spring frost
Dates the last frost of spring typically ends. Plant tender crops after the risk has passed for your comfort level.
| Frost intensity | Early (10%) | Average (50%) | Late (90%) |
|---|---|---|---|
| Light (36°F) | May 24 | May 8 | Apr 23 |
| Freeze (32°F) | May 13 | Apr 26 | Apr 7 |
| Hard (28°F) | Apr 26 | Apr 8 | Mar 24 |
| Severe (24°F) | Apr 10 | Mar 27 | Mar 11 |
Show full probability table (all thresholds & percentiles)
| °F | 10% | 20% | 30% | 40% | 50% | 60% | 70% | 80% | 90% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F | May 24 | May 19 | May 15 | May 11 | May 8 | May 4 | May 1 | Apr 29 | Apr 23 |
| 32°F | May 13 | May 7 | May 2 | Apr 30 | Apr 26 | Apr 23 | Apr 18 | Apr 14 | Apr 7 |
| 28°F | Apr 26 | Apr 20 | Apr 16 | Apr 12 | Apr 8 | Apr 5 | Apr 2 | Mar 30 | Mar 24 |
| 24°F | Apr 10 | Apr 5 | Apr 1 | Mar 30 | Mar 27 | Mar 24 | Mar 21 | Mar 17 | Mar 11 |
| 20°F | Mar 30 | Mar 25 | Mar 22 | Mar 18 | Mar 15 | Mar 12 | Mar 8 | Mar 4 | Feb 27 |
| 16°F | Mar 20 | Mar 16 | Mar 12 | Mar 8 | Mar 5 | Mar 1 | Feb 27 | Feb 22 | Feb 14 |
First fall frost
Dates the first frost of fall typically arrives. Count back by a crop's days-to-maturity to know your planting cutoff.
| Frost intensity | Early (10%) | Average (50%) | Late (90%) |
|---|---|---|---|
| Light (36°F) | Sep 25 | Oct 8 | Oct 22 |
| Freeze (32°F) | Oct 5 | Oct 19 | Nov 1 |
| Hard (28°F) | Oct 15 | Oct 31 | Nov 13 |
| Severe (24°F) | Oct 27 | Nov 10 | Nov 29 |
Show full probability table (all thresholds & percentiles)
| °F | 10% | 20% | 30% | 40% | 50% | 60% | 70% | 80% | 90% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F | Sep 25 | Sep 30 | Oct 3 | Oct 5 | Oct 8 | Oct 10 | Oct 14 | Oct 17 | Oct 22 |
| 32°F | Oct 5 | Oct 9 | Oct 13 | Oct 16 | Oct 19 | Oct 23 | Oct 26 | Oct 29 | Nov 1 |
| 28°F | Oct 15 | Oct 21 | Oct 25 | Oct 28 | Oct 31 | Nov 2 | Nov 4 | Nov 8 | Nov 13 |
| 24°F | Oct 27 | Nov 1 | Nov 4 | Nov 7 | Nov 10 | Nov 13 | Nov 17 | Nov 22 | Nov 29 |
| 20°F | Nov 8 | Nov 13 | Nov 17 | Nov 21 | Nov 26 | Nov 30 | Dec 3 | Dec 7 | Dec 13 |
| 16°F | Nov 20 | Nov 29 | Dec 2 | Dec 5 | Dec 9 | Dec 14 | Dec 18 | Dec 23 | Dec 31 |
Growing season is measured at 32°F with about 50% probability. Hardiness zone from the 2023 USDA map; frost normals from NOAA 1991-2020.
Where this data comes from
@endif These dates are computed from the nearest official weather station with long-term records: York 3 Ssw Pump Stn, Pa, about 2.8 miles away@if(!empty($station['elevation_ft'])), at 390 ft elevation. The further the station and the greater the elevation difference from your yard, the more your local frost timing can vary.
How we calculate these dates
Frost and freeze dates come from the NOAA 1991–2020 U.S. Climate Normals, the National Oceanic and Atmospheric Administration's 30-year averages for each weather station. A date shown at the 50% level is the median: in half of years the frost falls on or before it. The 10% and 90% columns show the early and late ends of the range, so you can plant on the odds you're comfortable with. These are long-term averages, not a forecast for this year - always check your local outlook before planting.
Source: NOAA National Centers for Environmental Information, 1991–2020 Climate Normals (public domain). Harman is not affiliated with or endorsed by NOAA.
Frequently asked questions
When is the last frost in Jacobus, PA?
On average, the last spring frost (32°F) around Jacobus, PA is about Apr 26. In cooler years it can run later, so for a safer bet many gardeners wait until Apr 7.
When is the first frost in the fall?
The first fall frost around Jacobus, PA typically arrives about Oct 19. Count back by a crop's days to maturity to find the latest date you can plant it.
When can I plant tomatoes and other tender crops?
Tender crops like tomatoes, peppers and basil are damaged by frost, so wait until the last spring frost has passed - around Apr 26 on average, or Apr 7 to be safe most years.
How long is the growing season here?
The frost-free growing season (between the last spring and first fall 32°F frost) is about 177 days in a typical year.
Are these dates a forecast for this year?
No. They are 30-year averages from the NOAA 1991–2020 Climate Normals, not a prediction for the current year. Use them for planning and always check your local weather forecast before planting or protecting crops.
Local weather for 17407 Planting calendar → Pennsylvania frost dates →
Data source: NOAA 1991–2020 Climate Normals · Page updated Aug 4, 2026